An experimental study on the impact of bioflocculation on activated sludge separation techniques

摘要: Abstract Membrane bioreactors have become a well-established alternative for conventional activated sludge systems with filtration instead of sedimentation step to separate the from purified water. Both separation processes, however, depend on good bioflocculation their performance. Small constituents are known be detrimental in filtration, while poor settling can often attributed improper floc formation. Therefore, aim this paper is further unravel relationship between and processes. To end, synthetic influents different mono-over-polyvalent (M/P) cationic compositions used create sludges morphologies states during 178 days experiment. The were characterized by microscopic image analysis, relative hydrophobicity, extracellular polymeric substances, subjected sedimentation, dead-end submerged crossflow tests. deflocculating effect high M/P ratio affirmed, inducing release colloidal material that caused severe fouling. Sludge flocs became empty did not settle well. In low reactor, overall better performance was observed but non-expected filamentous bulking episode bad settleability filterability, filterability since porous, well structured fouling layer formed. Hence, it concluded tests cannot asses MBRs big contribute cake ensure its porosity way. Hydrophobicity generally higher reactor might an abundance filaments part testing period. No conclusive information could extracted regarding role EPS, thus use EPS as or indicator (again) questioned.